Summary

A new -XshowSettings:system suboption has been added to display the system or container configuration. This option is only available on Linux systems.

Problem

A new jdk.internal.platform API has been introduced in JDK11 that allows the JDK to have access to Linux container or host configuration. This API will most likely be used by tools such as JMX or JFR but It would also be a useful diagnostic tool to allow the -XshowSettings to present the config data to end users.

Solution

Add a "system" suboption to -XshowSettings that will dump the system configuration data to stdout.

Specification

     -XshowSettings:system
                       (Linux Only) show host system or container
                       configuration and continue

On non Linux systems, this suboption will be ignored and all available
settings will be printed.  This suboption may be supported on non-Linux
systems when the jdk.internal.platform API implementation support is
added.


        The output generated is an implementation detail.  Here is a sample of what 
        might be provided:

        Operating System Metrics:
            Provider: cgroupv1
            Effective CPU Count: 24
            CPU Period: 100000
            CPU Quota: -1
            CPU Shares: -1
            List of Processors, 24 total: 
            0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 
            List of Effective Processors, 24 total: 
            0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 
            List of Memory Nodes, 2 total: 
            0 1 
            List of Available Memory Nodes, 2 total: 
            0 1 
            CPUSet Memory Pressure Enabled: false
            Memory Limit: Unlimited
            Memory Soft Limit: Unlimited
            Memory & Swap Limit: Unlimited
            Kernel Memory Limit: Unlimited
            TCP Memory Limit: 2048.00T
            Out Of Memory Killer Enabled: true